A note on the estimation of selective values from recaptures of marked animals when selection pressures remain constant over time

Summary An equation is given for the estimation of selective values from data obtained by mark-recapture experiments, assuming that selective pressures remain constant while the experiments are carried out. The equation does not have an explicit solution but can readily be solved using a trial-and-error method. The use of the equation is illustrated on some data reported byKettlewell et al. (1969) from an experiment involvingtypica andedda morphs of the mothAmathes glareosa. It is found that theedda morph apparently had a selective advantage of about 12% per day compared to thetypica morph and that this is significantly different from zero. Using another methodKettlewell concluded that the selective advantage of theedda morph was only 7% and that this was not statistically significant.     

Men matter: Additive and interactive gendered preferences and reproductive behavior in kenya

The extent of men’s roles in reproductive decision-making in Africa is a subject of contention. Despite the volume of work on the roles men play in fertility decisions, there have been few attempts to derive direct empirical estimates of the effect of men’s preferences on reproductive behavior. I employ 1989 and 1993 Kenya Demographic and Health Surveys to examine the relative roles of the reproductive preferences of males and females on contraceptive use. Additive and interactive measures of preferences document a significant effect of men’s preferences, which may eclipse women’s preferences. The implications of these findings are discussed.     

Wild foods and household food security responses to AIDS: evidence from South Africa

Wild foods may offer unique benefits to households afflicted by AIDS, providing a nutritious and freely available food source at minimal labour and financial costs. This article presents the results of food security assessments in two rural South African sites. Detailed household dietary recalls from 227 households, combined with qualitative work, explored the association of household AIDS proxies (recent morbidity, mortality and orphan fostering) with household food security and dietary composition. The study found that AIDS-proxy households were significantly more food insecure, and households fostering orphans were both poorer and more food insecure. Wild foods were evident in 40.3% of the 48 h recalls, with significantly greater likelihood of use in households with fostering paternal orphans, and/or with at least one AIDS proxy. Only paternal orphans were significantly associated with likelihood of using wild foods when controlling for household socio-economic status. Qualitative data suggests that households afflicted by AIDS might curtail their use of wild foods due to household labour shortages and stigma. This is unfortunate, as regressions indicate that households using wild foods may be more economically resilient. This may be particularly important for households registering AIDS proxies, due to a demonstrated negative correlation between accumulated household AIDS proxies and household income.     

A RECONSIDERATION OF THE ‘GREAT RATIOS’ OF ECONOMICS

Autocorrelations are found in the disturbance terms of regressions employed by L. R. Klein and R. F. Kosobud in a global model of growth employing five celebrated ratios of economics. This paper summarizes the Klein-Kosobud conclusions, modifies them by removing the autocorrelations, and extends the model to include more recent years. The modified conclusions hold even with the added observations.     

DETERMINING THE APPROPRIATE DISCOUNT RATES IN PURE CAPITAL RATIONING

This paper proposes an interpretation of the pure capital rationing problem as it is faced by many managers in decentralized firms in which budgets serve as the principal means of control. It is argued that the appropriate objective for situations such as these is the maximization of either undiscounted earnings over the planning horizon or total value of the investments at the horizon. When either objective function is used in conjunction with the frequently encountered linear programming models for the capital rationing problem, shadow prices result which give rise to discount rates that will reproduce the optimal solution using discounted cash flow as a criterion. These results are then used as a means for clarifying several confusing and misleading statements that have appeared in the literature.     

THE EFFECT OF MASCULINE AND FEMININE BRAND NAMES ON THE PERCEIVED TASTE OF A CIGARETTE *

The purpose of the current study was to determine whether brand name can affect the public's evaluation of a product. All subjects smoked identical cigarettes. One group of subjects, however, knew the cigarettes by the name of “Frontiersman,” a masculine name, while the other group knew the cigarettes as “April,” a feminine name. Male and female subjects were asked to rate the cigarette on seven measures. Results show that women gave a more positive evaluation to the cigarette purportedly named “April,” while men gave a more positive evaluation to the identical cigarette when they thought it was named “Frontiersman.” In addition, women reacted more strongly than did men to brand name influence.     

TEACHING EFFECTIVENESS IN THE DECISION SCIENCES: THE USE OF STUDENT EVALUATIONS

This article presents the results of an AIDS-sponsored investigation of teaching effectiveness in the decision sciences. Two national samples were employed in the study: a sample of 247 business school deans and a sample of 3,292 students from 32 different business schools. Included among the findings are that 87 percent of the deans responding indicate they require some sort of faculty teaching effectiveness evaluation, and that great care must be exercised when interpreting student ratings of an individual instructor's teaching effectiveness.